High-rise buildings in HCMC are covered in thick haze in the morning of September 22, 2019. Photo by VnExpress/Thanh Nguyen.

Saigon should check its air quality every day instead of every third day, the municipal environment department says.

The quality of HCMC air should be detected three times per day on a daily basis, the city Department of Natural Resources and Environment said Friday in a plan it proposed for next year.

Data on air quality will be collected at 7:30-8:30 in the morning when city people are on their way to work, 3-4 in the afternoon when the traffic flow is at its daily average, and 8-9 at night when trucks are allowed to enter the downtown area and people usually join outdoor entertainment activities, it suggested.

The department also wants to monitor superfine particles PM10, particulate matter 10 micrometers or less in diameter, and PM2.5, particulate matter, 2.5 micrometers or less in diameter, every 24 hours.

Following the samples it collects every day, the department will analyze and then announce the concentrations of pollutants (nitrogen dioxide, sulfur dioxide, carbon monoxide, and suspended dust), noise level, the levels of PM 10 and PM 2.5 on its website and mobile app.

HCMC currently has 30 air monitoring stations.

So far, the city has been collecting air quality data and analyzing it manually. It takes three-five days to announce the results.

According to the environment department, its proposal on increasing the monitoring frequency aims to keep both city residents and the administration informed until the city is equipped with a comprehensive environmental monitoring system costing VND495 billion ($21.3 million). The first system of its kind in Vietnam is expected to be go into service by 2022.

The air quality index in the city has reached very unhealthy levels on many days since September. Authorities have said exhaust from around 10 million vehicles is one of the three major causes of air pollution in the city, besides smoke from 1,000 large factories and dust from numerous construction sites.

By 2030 the city plans to install 16 more air monitoring stations at major intersections, residential areas and industrial parks.